The Bell's wwWorld!!! site was created by a Grade 9 Science teacher
in Ontario. Check it out for useful information on matter, and even
a WHMIS safety quiz.
Everything You Wanted to Know about Plasma
Everything you want to know about plasma, and more! Click on Basics,
then on What are Plasmas? for a great overview, including a photograph
of the Eagle Nebula and an excellent graphic that clearly illustrates
the differences between the four states of matter.
More Info on Plasma
This detailed site gives lots of examples of plasma and where to find